Lifting jacks



FIG. 1 is a perspective view of a lifting jack showing my new design;

FIG. 2 is another perspective side view thereof;

FIG. 3 is a backside view thereof;

FIG. 4 is a front side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is a top view thereof. 

CLAIM The ornamental design for the lifting jack, as shown and described. 